Use of polymeric additives such as amine oxides as an antioxidant or phosphites is known in the polymer industry. For example, phosphites (commercially available in liquid and solid forms) are antioxidants used to improve color, processing, heat and UV stability in a wide array of polymers, including polyolefins, ABS, synthetic rubber, PVC and more; amine oxides are hydrolytically stable high performance melt process stabilizers, for use in proprolyene, styrenics, and other polyolefins. The liquid additive has certain drawbacks, e.g., the handling of the liquid itself as well as its limited applications because certain applications or set-up cannot accommodate liquid stabilizers and can only handle solid materials. With respect to additives in the solid form, the handling of additives in a powder/dust form can sometimes be problematic. Therefore, it is preferred that low-dusting and easily feedable solid additives are used.
It is known in the art to incorporate certain additives into certain “carriers.” EP 138 203 discloses the mixing of certain additives, slip agent, with silica gel. However, the resulting product is not necessarily a free-flowing material that lends itself to convenient processing. U.S. Pat. No. 6,294,505 discloses the incorporation of additives including slip agents, antioxidants, light stabilizers, flame-retardant agents, etc. into anti-blocking agents such as silica gels, for a free-flowing powder which does not agglutinate and can be incorporated into polyolefins for processing and producing polyolefin films.
U.S. Pat. No. 4,247,498 discloses “carriers” as microporous polymers in various forms and shapes as films, blocks, and intricate shapes. The reference also discloses the preparation of microporous materials by heating a thermally stable liquid with a polymer and cooling to certain temperature, in which thermaodynamic non-equilibrium liquid-liquid phase separation is initiated. It should be noted that the material to be used herein should be thermally stable at the condition of operations.
Applicants have surprisingly found an inexpensive and convenient approach to deliver additives in the form of stabilizers, such as amine oxides and phosphites to meet the polymer processing needs, with the end results being comparable or better than in the prior art additives in a liquid or solid powder/pellet form.